The EU summit’s potential for stemming the eurozone debt crisis hinges on Germany, says CFR’s Sebastian Mallaby. "The central question in the European summit is whether there can be enough rule building to satisfy Germany, in order to liberate enough money to stabilize the weaker economies," Mallaby says. For the European Central Bank to intervene more forcefully in the markets, Mallaby says, what is needed is "some kind of compact that pushes the system towards more rules against excess borrowing by governments in the future to satisfy the German voters that they’re not sending money down a bottomless pit."

The role of the Federal Reserve has transformed in the past decade, as it has deployed trillions of dollars to boost the U.S. economy while expanding its regulatory oversight of the nation’s financial system.